This invention relates to a plain bearing intended for use in internal combustion engines. More particularly, the present invention relates to a multilayer plain bearing for engine connecting rods and crankshafts.
Multilayer plain bearings are well known in the art and widely used. One typical multilayer bearing is the so-called trimetal bearing, composed of a backing plate, usually of steel or aluminum, one intermediate layer, generally an aluminum or copper alloy, sometimes a diffusion or bonding layer, of nickel, aluminum, zinc or alloys thereof, and a sliding layer, generally a copper-tin-lead alloy. This type of bearing exhibits good properties as regards resistance to fatigue and wear, embeddability of foreign particles, conformability to accommodate shaft misalignments, and corrosion resistance.
However, for certain applications it would be desirable and advantageous to have a plain bearing the sliding layer of which, at the same time as it would keep the properties of corrosion resistance, embeddability and conformability unchanged, would have its material structured in such a manner as to impart to the sliding layer a higher resistance to wear and especially to fatigue which, as is known, is caused by cyclic loads on the bearing. It is, therefore, the main object of the present invention to provide a multilayer plain bearing having a sliding layer exhibiting at the same time excellent properties of embeddability, conformability, and corrosion, wear and fatigue resistance.